Many methods of sewer system rehabilitation are available to correct structural defects and reduce I/I. While it was once common practice to remove and replace deteriorated pipelines, this practice is becoming more limited due to the rise in popularity and availability of trenchless technologies.
Chemical grouting technology is used primarily for spot repairs to seal joints, small holes, and non-structural cracks of sewer lines, manholes or pump station wet wells. Chemical grouting does not improve the structural strength of a pipeline but when properly applied, does reduce or stop infiltration. This method should not be considered for pipe segments that are severely cracked, crushed, or broken. Choice of grouting composition is determined once each affected area has been independently evaluated.
This restorative method for aging pipelines is accomplished by inserting a new pipe within the old pipe. In a push-pull fashion, a flexible liner pipe slightly smaller in diameter is fed into the existing pipeline. This technology is especially effective for pipeline applications where extensive damage or corrosion has been confirmed, i.e., heavy cracking, unstable soil conditions, flat grade, or massive root intrusion.
As the leading rehabilitation alternative to traditional pipe system replacement due to its cost-effectiveness and risk reduction, this solution involves inserting a felt tube infused with resin into the affected pipeline and heating it to create a new cured-in-place pipe. Installing this flexible, corrosion-resistant, internal cured-in-place liner can significantly extend the life of existing sewer lines. CIPP lining solutions are well suited for bridging gaps and misaligned pipes, working in and around curved areas and under existing structures or busy traffic areas. Because the new pipe interior is smooth and has no joints or seams, customers may also see improvement in hydraulic flow capacity.
Another trenchless rehabilitation lining option, geopolymer, utilizes monolithic mineral polymer with ceramic properties to seal and repair existing pipelines and manholes. Unlike traditional cement-based mortars, geopolymer adheres to any structure surface and is capable of bonding and building layers of desired thickness. Geopolymer is most ideal in low-PH environments and has a higher resistance to acids. This lining option easily navigates line deformities or irregularities and is typically applied in pipes, culverts, and tunnels (metal, concrete, brick, or stone). Geopolymer is composed of over 50% recycled material, and its low carbon footprint makes it the most sought-after sustainable material option.